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ASCII Stereogram
ASCII stereograms are a form of ASCII art based on stereograms to produce the optical illusion of a three-dimensional image by crossing the eyes appropriately using a single image or a pair of images next to each other. To obtain the 3D effect (in Figure 1 for instance), it is necessary for the viewer to diverge their eyes such that two adjacent letters in the same row come together (Stereogram guide parallel.png). To help in focusing, try to make the two capital Os at the top look like three. Ensure that the image of the central dot is stable and in focus. Once this has been done, look down at the rest of the image and the 3D effect should become apparent. If the Os at the bottom of Figure 1 look like three, then the effect is reversed. It is also possible to obtain opposite 3D effects by crossing the eyes rather than diverging them (Stereogram guide cross-eyed.png). ---- Figure 1: Near and far distances. O O n n n n n n n n n n n n n n n n n f f f f f f f f f f f f f f e e e e e e e e e e e e e e e e e a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r O O Figure 2 demonstrates the effect even more dramatically. Once the 3D image effect has been achieved (Stereogram guide parallel.png), moving the viewer's head away from the screen increases the stereo effect even more. Moving horizontally and vertically a little also produces interesting effects. Figure 3 shows a Single Image Random Text Stereogram (SIRTS) based on the same idea as a Single Image Random Dot Stereogram (SIRDS). The word "Hi" in relief can be seen when the image clicks into place. (Stereogram guide cross-eyed.png) Some people have included stereograms in their "signature" at the end of electronic mail messages and news articles. Figure 4 is such an example. ---- Figure 2: A floor, wall and ceiling. O O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ---- Figure 3: A single image random text stereogram. O O OIWEQPOISDFBKJFOIWEQPOISDFBKJFOIWEQPOISDFBKJFOIWEQPOISDFBKJF EDGHOUIEROUIYWEVDGHOXUIEROIYWEVDGHEOXUIEOIYWEVDGHEOXUIEOIYWE KJBSVDBOIWERTBAKJBSVEDBOIWRTBAKJBSOVEDBOWRTBAKJBSOVEDBOWRTBA SFDHNWECTBYUVRGSFDHNYWECTBUVRGSFDHCNYWECBUVRGSFDHCNYWECBUVRG HNOWFHLSFDGWVRGHNOWFGHLSFDWVRGHNOWSFGHLSDWVRGHNLOWSFGLSDWVRG YPOWVXTNWFECHRGYPOWVEXTNWFCHRGYPOWNVEXTNFCHRGYPWOWNVETNFCHRG SVYUWXRGTWVETUISVYUWVXRGTWVETUISVYUWVXRGWVETUISVYUWVXRGWVETU WVERBYOIAWEYUIVWVERBEYOIAWEYUIVWVERBEYOIWEYUIVWLVERBEOIWEYUI EUIOETOUINWEBYOEUIOEWTOUINWEBYOEUIOEWTOUNWEBYOETUIOEWOUNWEBY WFVEWVETN9PUW4TWFVEWPVETN9UW4TWFVETWPVET9UW4TWFBVETWPET9UW4T NOUWQERFECHIBYWNOUWQXERFECIBYWNOUWFQXERFCIBYWNOFUWFQXRFCIBYW VEHWETUQECRFVE[VEHWERTUQECFVE[VEHWQERTUQCFVE[VEOHWQERUQCFVE[ UIWTUIRTWUYWQCRUIWTUYIRTWUWQCRUIWTXUYIRTUWQCRUIBWTXUYRTUWQCR IYPOWOXNPWTHIECIYPOWTOXNPWHIECIYPONWTOXNWHIECIYLPONWTXNWHIEC R9UHWVETPUNRQYBR9UHWVETPUNRQYBR9UHWVETPUNRQYBR9UHWVETPUNRQYB Figure 4: A stereogram signature. IIIIIIIIIIIIIII IIIIIIIIIIIIIII H ( ) \|/ H H ( ) \|/ H H( ) -O- H H ( ) -O- H H )/|\ H H ( ) /|\ H H =^ =H H =^ =H H- |----@-----H H----| ---@---H H /|\ @\|/ @ H H /|\@ \|/@ H H \|/ \|/ H H \|/ \|/H III^IIIIIII^III III^IIIIIII^III Wide eyed stereo Wide eyed stereo Moving animated versions of ASCII stereograms are possible too. ---- Text emphasis The stereo effect can be used to highlight individual words in a text, as a sort of "secret message". The effect can be disguised when the paragraph is block justified. ---- Figure 5: Emphasized single words. According to the According to the police inspector, police inspector, Edward John Billings, Edward John Billings, there are too many there are too many individuals too close individuals too close to the case to make to the case to make an arrest. I asked an arrest. I asked Mary Smith to comment Mary Smith to comment on the case, but she on the case, but she declined to comment, declined to comment, because she is soon because she is soon to be married to to be married to Howard D. Fredericks, Howard D. Fredericks, the victim's uncle. the victim's uncle. Charles Wilson, the Charles Wilson, the victim's brother, victim's brother, stated that the chaos stated that the chaos was responsible for was responsible for at least five suicide at least five suicide attempts last week attempts last week alone. alone. Sources Figures 1, 2, 3 and 4 are due to David B. Thomas, Jonathan Bowen, Charles Durst and Marty Hewes respectively. These four stereograms appeared on the publicly accessible alt.3d USENET newsgroup. Figure 5 was invented on the spot by a Wikipedian. Originally adapted from an article on ASCII Stereograms by the author of that article (and with his permission).